Semiconductor light emitting device and method of manufacturing the same

1. A semiconductor light emitting device comprising: a first undoped semiconductor layer including an uneven top surface; a first conductive semiconductor layer; an active layer formed on the first conductive semiconductor layer; and a second conductive semiconductor layer formed on the active layer, wherein the first undoped semiconductor layer includes first portions having a plurality of dislocations being spaced apart from each other and second portions not including the first portions, and a top part of the first portions protrudes relative to a top part of the second portions.

2. The semiconductor light emitting device as claimed in claim 1 , further comprising a buffer layer under the first undoped semiconductor layer and a substrate under the buffer layer.

3. The semiconductor light emitting device in claim 1 , further comprising a second undoped semiconductor layer between the active layer and the second conductive semiconductor layer, wherein the second undoped semiconductor layer has a p-type dopant.

4. The semiconductor light emitting device in claim 3 , further comprising a third undoped semiconductor layer on the second conductive semiconductor layer.

5. The semiconductor light emitting device in claim 3 , wherein a thickness of the first undoped semiconductor layer is about 1 μm to 5 μm.

6. The semiconductor light emitting device in claim 3 , wherein the second undoped semiconductor layer has a thickness that is thinner than a thickness of the first undoped semiconductor layer.

7. The semiconductor light emitting device in claim 3 , wherein a thickness of the second undoped semiconductor layer is about 10 Å to 500 Å.

8. The semiconductor light emitting device in claim 1 , wherein a lower surface of the first conductive semiconductor layer has an uneven surface.

9. The semiconductor light emitting device in claim 1 , wherein a thickness of the second conductive semiconductor layer is about 10 Å to 2000 Å.

10. The semiconductor light emitting device in claim 1 , wherein the first undoped semiconductor layer is formed of a GaN based layer.

11. The semiconductor light emitting device in claim 1 , wherein a thickness of at least one of the first portions in the first undoped semiconductor layer is thicker than a thickness of an area in the first undoped semiconductor layer where no dislocation exists.

12. A method of fabricating a semiconductor light emitting device, the method comprising: forming a first undoped semiconductor layer; forming a first conductive semiconductor layer on the first undoped semiconductor layer; forming an active layer on the first conductive semiconductor layer; and forming a second semiconductor layer on the active layer, wherein a top surface of the first undoped semiconductor layer is formed of an uneven surface, the first undoped semiconductor layer includes first portions having a plurality of dislocations being spaced apart from each other and second portions not including the first portions, and a top part of the first portions protrudes relative to a top part of the second portions.

13. The method as claimed in claim 12 , wherein at least one of the layers is exposed to a lamp when the layer is grown, and the lamp includes at least one of an Hg lamp, X-ray, an electron beam and a halogen lamp.

14. The method as claimed in claim 13 , wherein the first undoped semiconductor layer is exposed to the lamp when the first undoped semiconductor layer is grown.